Nventors



March 17, 1964 A. e. BALE, JR., ETAL 3,125,176

AUTOMATIC CONTROL FOR CUMULATIVE DELIVERY OF MATERIALS Filed Jan. 8,1960 3 Sheets-Sheet 1 if H \NVENTORS ALTON G.BALE, JR.

GREG F.TURNER BY jaws/j 5 ATTORNEY March 17, 1964 BALE, JR" ETAL3,125,176

AUTOMATIC CONTROL FOR CUMULATIVE DELIVERY OF MATERIALS Filed Jan. 8,1960 3 Sheets-Sheet 2 w E R.

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l 1 I l l I l l I AT TOR NEY March 17, 1964 A. ca. BALE, JR.. ETAL3,125,176

AUTOMATIC CONTROL FOR CUMULATIVE DELIVERY OF MATERIALS Filed Jan. 8,1960 3 Sheets-Sheet 3 lllllllllllllllllllllllll I! H .1. L 7 7 m h w w 0n M m M R f bl w N ;,4 7 5 7 Q 4 a a 1A 7 0 3 5 3 I 3 m olk 3 H HI I m az w 7 0 3 4! N N 0! U 0 0 III: 7 Z 6 6 B b 6 I 4/ 7 6 4D G! L 6 s 7 6 7R n 6 c l I k S r I l I I] III.

ATTORNEY United States Patent Ofi ice 3,125,176 Patented Mar. 17, 19643,125,176 AUTOMATIC CONTROL FOR CUMULATIVE DELIVERY OF MATERIALS AltonG. Bale, Jr., South Milwaukee, and Greg F. Turner, Brookfield, Wis.,assign'ors to Wisconsin Electrical Mfg. Co., Inc., Milwaukee, Wis., acorporation of Wisconsin Filed Jan. 8, 1960, Ser. No. 1,276 5 Claims.(Cl. 177-80) The present invention relates to an automatic control meansfor material delivery or positioning apparatus and particularly to anintegrating sensing control circuit. The preferred circuit may take theform of a voltage divider c rcuit or of a bridging circuit, if desired,and in which ClICIlllIS a signal amplifier may be preset to provide anamplified operating circuit to permit the motivation of controls forhopper batch gates or hopper discharge gates or for other means ofdischarging or positioning a selected material or commodity in whichcumulative weights of the separate materials or the cumulative positionsthereof may be automatically controlled without intermediate resettingoperations, and wherein the separate material weights or movementsthereof with respect to a fixed point may be individually set up on thecontrol panel by means of a control knob registering on a dial directlyrelated to each of the materials and preset according to the desireddelivered weights or positions thereof.

It is an object of the present invention to provide an automaticcumulative weight or positioning control means for delivery ofpreselected amounts or conveyor positions relating to individualmaterials or commodities and in which an operator may cumulativelycollect the materials in a hopper or at an established transportation ordelivery point by means of individual and independent settings ofsimplified control panel dials, and without requiring the operator tomentally add the weights or relative transportation positionsaccumulating in a final cumulative weight or position.

It is another object of the present invention to provide, in variousembodiments thereof, an automatic cumulative weight or positioningcontrol means including a plurality of voltage dividing circuits whichmay be alternatively matched with one another to reflect a balanced orunbalanced condition to an amplifying device for control of the deliveryof different materials accumulated at a fixed point, such as a hopper ora transportation or delivery position, and comprising in one of thevoltage dividing circuits a plurality of manually preset voltagedividing means selectively controlled by switch positioning means, andwherein the preset voltage dividing means is matched against a voltagedividing means directly reflective of the accumulated weight or positionof the delivered materials.

It is a further object of the present invention to provide, in one ofits embodiments, a plurality of voltage dividing potentiometersmechanically coupled with compensating potentiometers for maintaining afixed resistance in a comparative circuit portion, which circuit portionis arranged to be compared with a variable voltage dividingpotentiometer directly relating to the movement of a device indicatingaccumulated weight or positioning of a plurality of materialstransferred thereto.

It is still another object of the present invention to provide, inanother embodiment thereof, a mechanical compensating means forproviding an accumulative voltage division in one circuit of acomparative set of circuits for an automatic control for cumulativedelivery of materials of a preselected weight or delivery position.

It is a still further object of the present invention to provide anelectrical bridging circuit for indicating an unbalanced conditionsupplied to an amplifier between two comparative potentiometer circuits,in which one of said circuits includes a plurality of presetpotentiometers selectively added to one branch of the bridging circuitfor reflecting the said balanced or unbalanced condition.

It is still another object of the present invention to provide aclutching means for selectively establishing a comparative circuit forindicating a balanced or unbalanced condition for purposes of providinga signal to a signal amplifier for the delivery control of a pluralityof materials for establishing a fixed accumulative weight or deliveryposition thereof.

Heretofore, in the case of weighing or transporting a variety ofmaterials which are ultimately accumulated in a single Weigh hopper orat a preestablished fixed delivery point, the devices used incontrolling the amounts required an operator to mentally calculate theamounts to be delivered at the ultimate point or hopper, which was, inthe case of weighing materials, reflected in a single scale mechanicallycoupled with the hopper. Obviously, this required the attention ofsemi-skilled personnel, and even in cases where skilled personnel werepresent, the operation often permitted situations Where various errorsin calculation were introduced.

It will be apparent, that in the case of weighing ingredients for thepreparation of concrete for highway paving, for instance, that extensivetests and preestablished conditions have been scientifically set forthby engineers and persons professionally skilled in determining strengthand other factors of the finished and cured concrete, which factors aredirectly proportional to the amounts of cement, aggregate and sand andwater to be included in the initial mix. However, the final results ofthe mix are ultimately placed in the hands of the person in charge ofmaking the delivery of the raw materials. In many cases, these personsare unskilled laborers, who ordinarily Will not take the time, nor havethe inclination, to provide exact weights of raw materials fed to themixer.

The present invention is primarily directed to the automatic compilationof proper, preselected weights or relative positioning of materialswithout undue calculations of Weights or distances being required of theoperator placed in charge of dispensing the raw materials to betransferred to a common receiving means, such as a Weigh hopper, or tobe moved to a particular delivery point. Previous installations haveoften required the setting of circuit comparative means, such aspotentiometers, by first setting one potentiometer relating to, forinstance, sand at a desired value, and then requiring the operator tofirst account for the amount previously fed to the hopper and tomentally add to this amount the amount of another material, such asaggregate. This requires no particular effort in the case of easilyadded numbers such as pounds and 100 pounds, respectively, but ininstances where the figures might end in numbers other than zero, thecalculations require extra attention.

In installations embodying the present invention, however, the circuitryfor controlling the amount of material to be discharged, permits theoperator to merely select preset amounts on individual dials relating tothe respective materials, without requiring him to do any more than justthat. The integrating electrical circuitry automatically calculates theadditions for him.

The invention further consists in the several features hereinafter setforth and more particularly defined by claims at the conclusion hereof.

In the drawings:

FIG. 1 is a schematic circuit diagram of one embodiment of the controlcircuit of the present invention associated with diagrammaticallyillustrated components of a material delivery apparatus;

FIGS. 24, inclusive, are each portions of a schematic circuit diagram ofother embodiments of the control circuit of the present invention, andwhich portions may be read in combination with a portion of FIG. 1 whichis equally applicable to all embodiments of the invention and isillustrative of the material delivery apparatus and the circuitcomponents associated therewith. Referring first to the embodiment ofFIG. 1, it will be observed that the improved control, in one of itsapplications, may function to automatically control the delivery ofpreselected amounts of a plurality of materials, as for instance,material A and material B contained in individual storage bins and 11,respectively. A typical application of the invention may reside in theautomatic control and delivery of preselected weights of sand andaggregate fior use in the preparation of concrete at either a permanentsite or, in the instance of highway paving, from temporary installationsset up near the point of use. The storage bins 10 and 11 areconventional and permit the respective materials to be gravitydischarged through a bottom discharge opening 12. A suitable gate 13normally closes the discharge opening 12 to respectively retain thematerials A and B in the bins 10' and 11.

The gate 13 of each of the bins 10 and 11 is of a conventional jaw typehaving a pair of channel-shaped members pivotally secured to the wallsof the discharge opening 12. The jaws of the gate 13 are normallydisposed immediately below the opening .12 and are laterally swung fromunderneath the discharge opening to allow the respective material tofall freely from the bin to a weighing hopper 14. The weighing hopper 14is supported beneath the discharge opening 12 of each of the hoppers 10and 11 and is arranged to receive the free-falling column of materialtherein. The hopper 1 4 is coupled to a suitable scale 15 byconventional means diagrammatically illustrated herein. The scale isarranged to indicate the cumulative weight of materials A and B disposedin hopper 14.

A discharge opening 18 having a jaw-type gate 19, similar to the gates13 of the bins 10 and 11, is provided in the bottom of the weigh hopper14 to deliver the preselected quantity of materials A and B from thehopper 14 to any suitable transporting device, not shown, such as aconveyor belt, truck or the like.

Inasmuch as the control circuit portion, generally referred to by thereference character I, may be used as shown for purposes of illustratingeach of the various embodiments, it will be understood that theembodiments of the invention illustrated in the views of FIGS. 2-4 maybe substituted for the circuit portion indicated by the referencecharacter II of FIG. 1 in the descriptions thereof to follow. Thus, eachof the various control circuit embodiments may be interposed in thecircuit for automatic operation of the delivery control portion I bymeans of respective banks of a conventional step switch CRS which may becontrolled by a rotary solenoid or other means shown diagrammaticallyherein. Circuit portion I includes banks CRS1 and CRS-2 of the steppingswitch CRS, along with conventional homing contacts 20. Power issupplied by incoming lines 21 and 22 controlled by a master switch 23and provided with usual circuit protecting fuses 24 and 25. Thus, itwill be apparent from FIG. 1 that banks CRS-1 and CRS re- 7 spectivelycontrol, through their contacts, various means for actuating the jaws orgates 13 and 19 of the bins 10 and 11 and the weigh hopper 14,respectively. The manually operated start switch 30 and hopper dischargeswitch 31 respectively control the operation of the control circuit andthe final discharge of the contents from the weigh hopper 14, as willhereinafter be described. Thus, on completion of the circuit from lineconductor 21 through the movable contact 32 of bank CRS-1, when in itssecond operating position engaging stationary contact 33, and thence toconductor 34, the coil of solenoid 35 will be energized as the circuitpermits its plunger to open the discharge gate 18 of the bin 10. Theconductor 36 is connected to the coil of solenoid 37 to actuate itsplunger controlling the discharge gate 13 of the bin 11, and the circuitis completed from the coil of solenoid 3 7 to the power line 22 onmovement of contact 32 to its third position to engage stationarycontact 38. Conductor 39 terminating in the contact 40 of bank CRS-l ofthe stepping switch completes its circuit to the power line 22 throughthe coil of solenoid 41 controlling opening operation of the dischargegate 19 of the weigh hopper I114. The sequential operation of thevarious actuating solenoids or other means for opening the gates willlater be described. 7

Bank CRS-2 of the stepping switch will next be described, and it will beobserved that this bank is connected with the power line 21 by means ofthe branch conductor '49 and includes a movable contact 50 arranged forengagement with stationary contacts '51, 52, 53 and 54, of whichcontacts 52 and 53 are electrically connected to one another by means ofbridging connector 55. Contact 51 is normally connected at the initialor start position of contact 50, with the normally open, momentary,manually controlled, start button 30 interposed in the conductor 57. Thecontact 54, which is engaged by m-ovable contact 50 on the fourth stepposition of the switch CRS, is connected to the normally open contact 56of the relay OR by means of conductor 59. Both the conductors '57 and 59are arranged to complete the circuit from the power line 21 to thehoming contacts 20, through the branch circuit 60. The homing contacts20 are conventionally supplied with stepping switches of the typedisclosed herein to break the circuit between each steppiiig positionfor purposes of permitting the switch operating mechanism, such as asolenoid plunger, to return to its normal home position.

'Normally closed contacts 61 of the relay CR are also connected to theoperating element of the stepping switch CRS by means of the branch 60and the conductor 62 terminating in the bank CRS-2 contact 53, whichwill be recalled is also in circuit connection with contact 52 by meansof the bridging conductor 55. The sensing control portion I I of thecircuit of FIG. 1 includes a group of voltage dividing Potentiometersarranged to divide a DO. circuit supplied from a transformer 70 havingits primary winding 71 to the power input conductors 21 and 22 andincluding a secondary winding 72 supplying a DC rectifier 73. Asecondary winding 74 provides power input to the signal amplifier 75.The DC. supply is provided from conductors '76 and 77 oppositelyconnected to the rectifier 73.

The sensing circuit portion II further includes a scale potentiometer 80which is mechanically coupled to the dial of the scale 15 and arrangedto have its movable contact member 81 rotate in correspondingrelationship with the dial of the scale 15. It is conceivable that alinearly movable potentoimeter may be utilized and arranged to have itscontact move over a proportionate portion of the winding correspondingto the movement of the scale dial or other indicating scale means (notshown). The mechanical coupling between the scale 15 and potentiometercontact 81 is not specifically shown, but it is conceivable that themovable contact 81 may be in direct coaxial relationship with a commonlaterally extending rotatable axle on the scale indicator or indirectlymotivated by a servo device. The movable contact 81 is electricallyconnected to one side of the signal amplifier 75 by means of theconductor 82. A compensating resistor R is provided, when desired.Preset potentiometers 83 and 84 are provided which are preferablymechanically coupled with compensating potentiometers S and 86,respectively, and are arranged to be connected across the DC. supplycircuit conductors 76 and 77 by means of a branch line 87 connectingconductor 76 with potentiometer 83, branch conductor 88 connecting themoving contact 89 of preset potentiometer 83 with the presetpotentiometer 34, branch conductor 90 connected to the moving contact 91of preset potentiometer 84, the moving contact 92 of the compensatingpotentiometer 85, the winding of compensating potentiometer 86, branchconductor 93, the moving contact 94 of compensating potentiometer 85, tocomplete the circuit to conductor 7'7 by means of the winding ofcompensating potentiometer 85 and branch conductor 95.

The moving contact 89 of the preset potentiometer 83 (whichpotentiometer relates to material A) is electrically connected to thestationary contact 97 of the CRS-3 bank of the stepping switch CRS,which also includes stationary contacts 96, 97, 98 and 99. Theconnection between movable contact 89 of potentiometer 83 and thecontact 97 is made via branch conductor 100, whereas another circuit iscompleted from movable contact 91 of preset potentiometer 84 to contact98 by means of branch conductor 101. Preset potentiometer 84 relates tomaterial B, as will hereinafter be described. Contact 99 of bank CRS-3is connected with the moving contact 102 of a zero sensing potentiometer103 by means of branch conductor 104. The potentiometer 103 is arrangedto divide the circuit between conductors 76 and 77 and includes acompensating resistance 104a. The movable contact 105 of bank CRS3 isdirectly connected to the signal amplifier 75 by means of branchconductor 106. The signal amplifier is arranged to amplify signalsreceived from the conductors 82 and 106, sensing an unbalanced conditionbetween the scale potentiometer 80 and the circuits completed by therespective positions of contact 105 of bank CRS-3. The signal receivedby the amplifier is amplified and fed to conductors 107 and 108, whichsupply the coil 109 of the sensing relay CR.

Operation of the circuit components of the embodiment of FIG. 1 willnext be explained. Initially, it is to be assumed that the scale 15 andscale potentiometer contact 81 are at zero reading, and that thematerial A preset potentiometer 83 has been manually set at an assumedposition of 200 lbs., and the material B preset potentiometer contact 91position is also set at an assumed value of 200 lbs, to provide a totalweight of 400 lbs. on the scale 15 at the conclusion of batchingprocedures. The movable contacts 89 and 91 of preset potentiometers 83and 84, respectively, are manually controlled by the operator andconventional indicator dials (not shown) are generally provided forpurposes of registering the desired preset position. As before stated,the stepp ng switch CRS is preferably solenoid actuated and includes thenormally closed homing contact 20 and the three banks CRS-l, CRS2 andCRS3 having four contacts apiece. The moving contact of each of therespective stepping switch banks is ganged to operate concurrently withthe other contacts or in otherwise fixed relationship with therespective moving contact of the other two banks.

Initially, we will assume for illustrative purposes that the step switchCRS is in its start position with the moving contact 32 of bank CRS-lbeing positioned relative to an unconnected contact, whereas the movingcontact 50 of CRS2 is in its first position connecting the power line21, through the branch 50, to the stationary contact 51, to therebysupply power to the conductor 57 upon manual closure of the switch 30.The moving con- '6 tact 105, in its start position relative to contact96, does not supply any circuits through its first contact.

When an operator readies the control circuit for operation, upon closingthe master switch 23, he is then ready to start the delivery of thepreselected amounts of material A and B (assumed to be at a position of200 lbs. in each case) by depressing the momentary start button 30. Thisoperation completes the circuit, and power is supplied to the operatingcoil of switch CRS, causing the step switch to step to the secondoperating position. Thus, the moving contact 50 of bank CRS-Z instepping from the first position to the second position breaks itscircuit with contact 51 to inactivate the start button 30. While in thesecond position it will be noticed that a circuit is completed on bankCRS-2 through contact 52 to the normally closed contact 61 of relay CRto the CRS coil, but because of the inherent delay in the operation ofthe step switch, the following steps take place before the step switchcan step. First, since the moving contact 105 of bank CRS-3 has alsomoved to its second position, it will now pick up the material A presetpotentiometer 83 through conductor 100, which potentiometer has beenpreset at a desired value of 200 lbs., and the scale 15 and itspotentiometer contact 31, at this moment will be at a zero reading. Itwill be observed, therefore, that the signal amplifier will sense anunbalanced voltage. This unbalanced voltage is amplified to conductors107 and 108 resulting in the energization of coil 109 of the sensingrelay CR. Thus, the normally closed contact 61 will now open to therebyprevent the step switch CRS from stepping out of its second positionuntil the CR contact 61 is again closed. It will also be apparent thatthe bank CRS-fl movable contact 32 is also in the second position atthis movement, permitting power from conductor 21 to reach the coil ofsolenoid 35 of the material A batch gate 13, resulting in the opening ofthis gate. Material will now flow from the overhead bin 10 into theweigh hopper 14, causing the scale to begin to deflect. As the weight ofmaterial builds up in the weigh hopper 14, the scale 15 will registerthe weight, and upon reaching an indication of 200 lbs., (suchindication having been previously set on the preset potentiometer 83), azero signal will be received by the signal amplifier 75, and the sensingrelay CR will drop out and remain in the dropped out position withcontact 61 being returned to its normally closed position.

At this time, a circuit will also be completed from the second positionof the bank CRS-Z, via contact 52 and conductor 62 through the nowclosed contact 61 to the coil of step switch CRS, allowing power toremain on the step switch coil until the step switch can position thethree ban-ks of contacts to their third position. In the third positionit will be apparent that the moving contact 105 of bank (IRS-3 picks upthe preset potentiometer 84 on engagement with contact 98 and conductor101. The contact 50 of bank CRS2 will again pick up the circuitincluding the normally closed contact 61 of relay OR through theconductor 62, and bank CRS-1 contact 32 picks up and energiezs the coilof batch gate solenoid 37 for gate 13 of bin 11, holding material B.Since the preset potentiometer 84 has been previously set at a value of20 0 lbs., the first impression will be that the circuit will remain atbalance, but further observation will indicate that the resistance inthe preset potentiometer 84 is in series with the resistance in thepreset potentiometer 83 through branch 88. Thus, while the presetpotentiometer 84 registers 200 lbs. on its dial, the amount of seriesresistance is actually equivalent to a value of 400 lbs. Therefore, withthe scale previously having stopped at 200 lbs, there now remains anunbalance difierentiation of 2-00 between the position of the scale 15and its potentiometer and the electrical position of the presetpotentiometer 84. Thus, with this unbalance existing the unbalance willagain be amplified by the signal amplifier 75, which in turn energizesthe sensing relay CR, causing the normally closed contacts 61 to againopen before the step switch CRS can step out of its third position.Material will now flow out of the material B batch gate 13 and the scale'15 attached to the weigh hopper will increase in its registration untilan indication of 400 lbs. is reached. At this point the electricalbalance again will occur where there will be a zero signal fed to thesignal amplifier 75, allowing the sensing relay CR to deenergize and thenormally closed contact 61 to again close. The contacts again remainclosed sufficiently long for the step Switch CRS to step from the thirdposition to the fourth position.

In the fourth position the contact 105 of bank CRS-3 will pick up aso-called zero sensing potentiometer 103 which is present and alwaysremains at the preset position to sense a zero balance when the scale isat zero. Therefore, since our scale registers well above the point forzero signal to be fed into the amplifier 75, the sensing relay CR must,by necessity, remain in its dropped off position until the scale reachesthe zero weight point to permit this relay to pick up. Parenthetically,the differential signal fed into the signal amplifier 75 that isresulting between the scale and the zero sensing potentiometer 103 is inefiect a negative signal which cannot be amplified. Therefore, the bankCRS-2 contact 54 is in series with a normally open contact 56 of relayCR providing an interrupted circuit to switch CRS. It will now beapparent that when CRS-1 contact 32 is in the fourth position contactingcontact 40, manual depression of the discharge button 31, will cause thedischarge gate 19 of Weigh hopper 14 to be opened by means of theactuator of solenoid 41, and the material in the weigh hopper 14 may bedischarged at will.

As the material in the hopper 14 is discharged, the scale will decreasein its registration until the weight hopper 14 becomes empty and thescale 15 registers zero. The zero sensing potentiometer 103 having beenset so that when the scale 15 is at zero, there will be justsufficiently unbalanced differential between the scale potentiometer 8'0circuit and the zero potentiometer 103 circuit for the sensing relay CRto be energized. Thus, the sensing relay CR picks up its contact 56,completing the circuit through the fourth position of the bank CRS-2 tothe coil of step switch CRS, causing the step switch to step on throughone more step on the start position. The cycle may now be again startedas described above at the wall of the operator.

As stated previously, the circuit including the preset potentiometers 83and 84 also includes compensating potentiometers 86 and 85 which arerespectively mechanically coupled with potentiometers 83 and 84. It willbe noted that the moving contacts 92 and 94 are arranged to cancel outthe resistance introduced by the relative positioning of the coupledcontacts 89 and 91 contacting the respective coils of potentiometers 83and 84. Thus, no matter when the preset contacts 89 and 91 may bepositioned, the eifect will be to maintain the same amount of resistancein the voltage divided circuit between conductors 76 and 77.

The embodiment of FIG. 2 will next be described and it will be apparentthat the schematic portion illustrated is equivalent to the portion IIof FIG. 1 and may be read in conjunction with the diagrammatic portion Iof that figure. It will first be noted that there is again provided twoseparate and individually adjustable preset potentiometers 110 and 111,both arranged to divide the circuit between the DC. conductors 76 and77.

' Like reference numerals will be used throughout the description toindicate like parts in the various embodiments.

The preset potentiometer 110 is related to the delivery of material Aand potentiometer 111 may be set for predeter-mined delivery of materialB. The circuit to the signal amplifier 75 from preset potentiometer 110is completed from its movable contact 112 to the branch conductor 113connected to stationary contact 115 of bank CRS-3a, which also includescontacts 114, 115, 116 and 117. The movable contact 118 of presetpotentiometer 11*1 completes its circuit through branch conductor 119 tothe contact 116. A zero sensing potentiometer 103 is connected throughits movable contact 102 to the bank contact 117 by means of the branchcircuit 104. DC. conductors 76 and 77 are bridged by the branchconductor 120 connected in series with the potentiometer 110, whereasbranch conductor 121 includes potentiometer 111 and the zero sensingpotentiometer 103 is connected across the conductors by means of branchcircuit 122. In this case the end terminals of the respective coils ofpotenti ometers 110 and 111 are connected in series with the conductors120 and 121, respectively.

It will be observed that the embodiment of FIG. 2 includes mechanicalcompensating means in substitution for the compensating potentiometersand 86 of the embodiment of FIG. 1, which means may comprise a bevelleddrive gear 120 arranged to be mechanically coupled with the movablecontact 112 of potentiometer 110, and manually rotatable by means of thehand wheel 121, which hand wheel may register the preselected amountupon an indicating dial (not shown), or other such means. For purposeswhich will later be apparent the beveled drive gear 120 is normallybiased out of meshing contact with its driven beveled pinion 122 bymeans of a spring 123 circumjacent to axially slidable shaft 124, andstationarily held at its opposite end. The driven gear 122 is arrangedto drive an oppositely disposed bevelled gear 122a which, in turn, mateswith a bevelled pinion 125. The bevelled pinion 125 is axiallymechanically coupled with the movable contact 118 of presetpotentiometer 111. The potentiometer 111 may be preset by means of themanually operated hand wheel 126 connected to a bevelled drive gear 127which is normally out of contact with its mating driven gear 128. Thedriven gear 127 is normally biased away from contact with driven gear128 by spring means 129 and when in engagement with gear 128 acts torotate beveled gear 12811 which is also in mesh with pinion 125.

Thus, it will be apparent that each of the individual presetpotentiometers and 111 may be individually set by means of the handdials 121 and 126, respectively.

The mechanical coupling arrangement of the preset potentiometers 110 and111, in the present embodiment, provides a means for automatically tyingin the two potentiometers without requiring dual matched unitsillustrated in connection with the first described embodiment. Thus,because of the direct coupling between the gears 122, 122a, 125, 128aand 128 of the gear train, manual rotation, and pressure against thebias of spring 123, of the hand wheel 121 will cause drive gear to meshwith driven gear 122 to provide concurrent movement of the movablecontacts 112 and 118 of the potentiometers 110 and 111, respectively. Ifit is assumed, as in the case of the first embodiment, that the movablecontact 112 of potentiometer 110, is set at an arbitrary 200 lbs. ofmaterial A, the contact 118 will also be caused to move a comparabledistance, signified by the dotted line position, on the winding of thepreset potentiometer 111 as the pinion 125, mechanically coupledthereto, is concurrently rotated during manipulation of the hand wheel121. This will add an equal number of coil turns in each presetpotentiometer.

To preset the potentiometer 111, relating to material B, the hand wheel126 is then pressed inwardly against the bias of its spring 129 androtated to an assumed position of 200 lbs. It will be observed thatmovement of the hand wheel 126 will have no effect on the position ofthe movable contact 112 of potentiometer 110, as the gear 120 will beout of contact with the gear 122.

Thus, one or the other of the potentiometers 110 or 111 may be left atZero position if only one of the materials A or B is desired.

It will be apparent that in each of the steps of the step switch CRS,such as those previously described in con-.

nection with the first described embodiment, that the voltage divisioninthe respective preset potentiometers 110 and 111 will be balancedagainst the scale potentiometer 80 contact 81 position. That is, whenthe step switch CRS has been actuated to motivate the movable contact123 of the bank CRS-3a to its second position, in contact with thestationary contact 115, there will be an unbalanced signal to the signalamplifier 75 until the contact 81 of the scale potentiometer 30 has beenmoved concurrently with the dial of the scale 15 to a relative positionindicating 200 lbs. of the discharged material A. When the movablecontact 123 has been actuated to its third position, in contact with116, the voltage comparison will be made from conductor 119 to themovble contact 118 of the preset potentiometer 111. Since the movingcontact 118 of potentiometer 111 has been previously motivated, uponrotation of gear 122 responsive to manipulation of hand wheel 121, tothe amount indicated by the dotted position on FIG. 2, the voltageunbalance will take into consideration the previously set amount of 200lbs. now registering on the dial of scale 15 because of discharge ofmaterial A, and reflected on the scale potentiometer 89. Thus, therelative electrically unbalanced condition will be reflected between thedotted position of the movable contact 118 and its solid line presetposition of 200 lbs. A balanced voltage condition will then exist whenthe movable contact 81 of the potentiometer 80 moves from its positionestablished from the 200 lbs. from material A discharged to the hopper14, to the new 200 lbs. weight position of material B preset as a limiton potentiometer 111.

Again, when the movable contact 123 of the bank CRS-3a moves to itsfourth position, in contact with contact 117, the zero sensingpotentiometer 1133 will be brought into play, sensing an unbalance, topermit actuation of the solenoid 41 for opening of the discharge gates19 of the hopper 14 upon manual closure of the switch 31 at the will ofthe operator.

Next, with reference to the embodiment of FIG. 3, this embodimentillustrates a further variation in the potentiometer circuit andincorporates a servo-mechanism drive for the so-called scalepotentiometer. In the circuitry illustrated in FIG. 2, there isindicated two individual single preset type potentiometers 130 and 131having movable contacts 132 and 133, respectively. These potentiometersrespectively relate to the material A and material B. In the case of thepresent embodiment, a clutch driven potentiometer 135 is provided withits movable contact 136 actuated by means of a suitable clutch mechanismthat is adapted to position itself in direct relationship to theposition of the dial of the scale 15. Also driven by thisservo-mechanism is a socalled reference potentiometer 137 having itsmovable contact member 133 coupled directly to the scale pointer shaft139 in order that its position directly reflects that of the scalepointer. A suitable gear train 140 may be provided for providing thedirect power through some means, such as a right angled drive, indicateddiagrammatically at 141 for the reference potentiometer 137 and forsupplying power to a clutch means 14-2. Power to the gear train 140 issupplied from a drive shaft 139, which may be connected directly to theshaft of the scale dial or, as shown, which may be empowered by means ofa servoreceiver 143 of conventional design receiving a power signal froman amplifier 144 which, in turn, receives its signal from a conventionalservo-transmitter 145.

The engaged element of the clutch 142 is preferably spring biased in apreferred direction by means such as a torsion spring 146 and alsoincludes a stop means 147 for maintaining the driven clutch member in apreferred home position, with the contact 136 of the potentiometer 135at zero position.

The clutch driven potentiometer 135 is inserted between the D.C. powersupply conductors 76 and 77 and connected thereto by means of a branchconductor 150, whereas the potentiometers 1 31i and 131 are connectedacross the lines by means of conductors 151 and 152, respectively. Azero sensing potentiometer 1113 is again supplied and connected in theusual manner. The movable contact 13 8 of the reference potentiometer137 is connected by means of branch conductor 153 to the fourth positionstationary cont-act 154 of a stepping switch bank CRS-3 b. The bankCRS-3b also includes a moving contact 155 and additional stationarycontacts 156, 157 and 158. The contacts 157 and 153 are electricailybridged by means of a conductor 159, both the contacts .157 and 158,representing the second and third position of the movable cont-act 136by means of conductor 160.

An additional bank CRS-4b is provided for the step switch CRS in thiscase and comprises a movable contact 165 and four stationary contacts166, 167, 16-8 and 169. The contact 167 representing the second positionof bank CRS-4b is connected to the moving contact 132 of the presetpotentiometer by means of a conductor 1711, whereas the con-tact 168 isconnected with the moving contact 133 of the potentiometer 131 by meansof conductor 171. The fourth position contact 169 of bank CRS-db isconnected in the usual manner with the movable conductor 102 of the Zerosensing potentiometer 103 by means of the previously described conductor104.

Both of the preset potentiometers 131i and 131 for mate-rials A and B,respectively, are set for the specific weights of the material that arerequired in the weigh hopper 14. Therei-ore, if the preset potentiometer130 is assumed to be set for 200 lbs. of material A and the presetpotentiometer 131 has its contact set for an assumed position of 200lbs. of material B, the following sequence will take place.

As the start button 30 (see FIG. 1) is closed, the step switch CRS willmove as previously described, to its second operating position tothereby close the circuit to the preset potentiometer 130 throughconductor 1715, contact 167, movable contact 1 65 and conductor 172 tothe signal amplifier 75. Simultaneously, the circuit to the clutchdriven potentiometer will also be closed through conductor 160, contact158, bridging conductor 159 and contact 157 of the bank CBS-3b, thenengaged by the movable contact 155. Contact is connected to the signalamplifier 75 by means of conductor 173.

Another circuit, which is conventional, merely supplies power from thesignal amplifier 75 through conductors 174 and 175 to the electricallydriven clutch 142, which circuit is also picked up at this time. Thus,as the material A flows from its hopper 10 into the weigh hopper 14, thescale 15 will indicate the weight and supply power to the clutch 142(now engaged responsive to the amplifier 75 signal output) to the clutchdriven potentiometer 135, which will respond in proportion to the amountof material A discharged, until the material reaches the assumed valueof 200 lbs. preset on potentiometer 130. A balanced signal will then bereceived by the signal amplifier 75. This will cause the stepping switchCRS to switch to its third posit-ion in its various banks, and theclutch 142 will concurrently be momentarily deenergized. Upondeenergizatlion oi the clutch 142, the potentiometer 135 will be resetto Zero position by means of the spring 146 and with the stop 1'47resting in its home or rest position, as shown.

Next, with the bank CRS-4b in the third position, with its movablecontact engaging stationary contact 168,

the preset potentiometer 131 will be picked up to provide discharge orfmaterial B. Again the clutch driven potentiometer 135 will start fromits Zero position, even though the dial of the scale 15 is registering200 lbs. (because of the previous weighing of discharged material A),because of disengagement of clutch 142. We will again weigh out theassumed preset 200 lbs. of material B; that is, until the clutch drivenpotentiometer 135 again reaches 11 the electrical balance point, atwhich time the step switch CRS will be caused to switch into its fourthor discharge position, as previously described. The discharge switch 31(see FIG. 1) may now be depressed to release the material firom weighhopper 14-.

It is possible under the present embodiment to provide an automatic tarecompensation to provide for any sort of weigh hopper. The hopper may bein the form of a truck or any receptacle resting on the scale 75 withunknown tare weight. The scale dial can read at any point, but theclutch driven potentiometer 135 will always start at Zero, assuring thecorrect final weight in the receptacle.

Referring next to the embodiment of FIG. 4, it will be apparent that theinvention may take the form of an electrical bridging circuit. That is,the main power supply is provided in the usual fashion from conductors21 and 22 to the primary winding '71 of transformer 70. The DC. circuitsupply is provided again by means of the rectifier 73, and the signalamplifier 75 receives its power from the secondary winding 74 of thetransformer 70, as previously described. Thus, a bridged circuit isestablished between the junctions 1 80, 181, 182 and 1-83, junctions 181and 18 3 being connected directly to the DC. circuit conductors 76 and77 originating from the rectifier 73. An unbalanced circuit conditionwill then be reflected in a signal to the signal amplifier 75 betweenpoints 180 and 182 and the respective conductors 18 4 and 185terminating in the amplifier 75. A fixed resistance is provided in theconventional manner for bridging circuits, in the form of resistor 186between the junctions 180 and 181, as is another resistor 187 providedin the bridge circuit between junctions 18 1 and 182. Again, a scalepotentiometer 188 has its moving contact 1 89 mechanically coupled withthe dial of the scale and arranged to move correspondingly with thatdial. Preset Potentiometers 190 and 191, having moving contacts 192 and193, are provided in one branch of the bridge between junctions 1'80 and183 and relate to materials A and B, respectively. These potentiometersare manually set as described in connection with previous embodiments.An alternate bridging circuit between junctions 1 80 and 18 3 includes azero sensing potentiometer 194 having a moving contact v195.

The present embodiment includes stepping switch CRS contact banks CRS-3cand CRS-4c, in addition to the banks CRS-1 and CRS- 2 illustrated in thecircuit portion I of FIG. 1. The bank CRS-3c includes a movable contact196 engageable with the stationary contacts 197, 198 the remainingcontacts relating to the third and tfourth stepping positions not beingused herein. The movable contact 200- of bank CRS-4c is arranged toelectrically engage the stationary contacts 201, 202, 208 and 4. Thecontacts 202 and 20 3 are connected with one another by means of thebridging conductor 20 5. The movable contact 200 of bank CRS-4c iselectrically connected to the junction 180 by means of a branchconductor 210 and is arranged to selectively complete the circuitbetween junctions 180 and 183 in conjunction with the bank CRS-3ccontacts, as will later be described. Contact 203 is also connected to aterminal 211 by means of conductor 2 1 2. The stationary contact 204 isconnected to the alternate bridging circuit between junctions 180 and183 including the movable contact 195 of the zero sensing potentiometer194, by means of conductor 213.

The movable conductor 196 of bank CRS-3c is connected, by means ofconductor 2.14 to one side of the presetting potentiometer 191 and isarranged to bypass this potentiometer when moved to its second positionin engagement with stationary contact 198. Contact 198 is connected tothe opposite side of potentiometer 191 by means of conduct-or 215. Bothpotentiometers 190 and 19 1 have one end of their windings free ofelectrical connection. There are no connections to the contacts relatingto the third and iourth positions of the 12 bank CRS-3c movable contact196. The opposite D.C. supply conductor 77 originating from therectifier 73 is connected to the point 181 of the bridging circuit.

It will be apparent that any unbalance in the bridging circuit reflectedbetween the junctions 180 and 182 will be reflected in a signal to thesignal amplifier 75, which accordingly will supply amplified current inthe usual manner to the coil 109 of the relay CR by means of conductors107 and 108. The switch CRS will operate in the manner previouslydescribed in connection with the embodiment of FIG. 1. Thus, with anassumed preset value of 200 lbs. of material A to be discharged, asestablished, by manual adjustment of the movable contact 1912 of thepreset potentiometer 190, and a preset amount of 200 lbs. of material Bestablished on the pre set potentiometer 191, it will be apparent thatwhen the movable contact 200 of bank CRS-4c is stepped to its secondposition, the circuit between junctions .180 and 18 3 will be completed.This circuit includes junction 180, conductor 210, contacts 200 and 202,connector 205, contact 203, conductor 212 and terminal 211. Inasmuch ascontact 196 of bank CRS-3c has also been concurrently stepped to itssecond position in engagement with contact 198, a bypass circuit willthereby be provided around the preset potentiometer 191 through conductors 214 and 215. It will then be seen that the branch circuitbetween junctions 180 and 183 will take the path through presetpotentiometer 190 for determining the preset amount of material A to bedelivered and as the material A is discharged from the bin 10, the dialof scale 15 will be caused to move and thereby concurrently move themovable contact v18 9 of the scale potentiometer 1188' to reflect anunbalanced condition in the circuit between the points 180 and 182. Theunbalanced signal will then be received by the amplifier 75 and theseveral ensuing actions will take place in the circuit portion I, aspreviously described in connection with the embodiment of FIG. 1. Abalanced circuit condition will be reached when the contact 189 matchesthe preset position of the contact 192 of the potentiometer 190,relating to material A.

As the movable contacts 196 and 200 of banks CRS-3c and (IRS-4c arecaused to step to their third position, respectively, it will beapparent that the circuits to the conductors 214 and 215 will each beinterrupted. This actuator will permit current to now be suppliedthrough the preset potentiometer 1191, and the resistance of thepotentiometer 191 will thereby be added to that of potentiometer 190.The dial of the scale 15 will have remained at its position indicating200 lbs. of material A, and accordingly, the contact 189 of the scalepotentiometer 188 will also reflect this position. As the movablecontact 200 is now at its third position in engagement with stationarycontact 203, the circuit will be completed from junction to the terminal211 through conductor 2 10, contact 200, contact 203 and conductor 212.Now, however, an unbalanced circuit relationship will again beestablished as the circuit includes the preset amount indicated by thecontact 193 of preset potentiometer 191, relating to material B.

As material B is discharged from its bin 11, the dial of scale 15 willagain be caused to move from the 200 lb. position previously establishedby discharge of material A, and will accordingly, cause the movablecontact 189 to move from its former position, relative topreviously-discharged material A, to a position representing the totalresistive circuit of potentiometers. 190 and 191 in the branch betweenjunctions 180* and 183 Upon reaching the assumed preset position of 200lbs. of material B, a balanced signal will again be received by thesignal amplifier 75 to thereby cause the discharge gate 13 of bin 11 toclose and to further cause the stepping switch to be motivated to itsfourth position, as previously described, and place the movable contactof bank CRS-4c in engagement with stationary contact 204. This will nowcomplete the circuit from junction 180 through conductor 210, movablecontact 200, contact 203, conductor 213 through the alternate circuit ofthe Zero sensing potentiometer 194 to be completed to the junction 183.The unbalanced circuit condition reflected through the alternate circuitof the Zero sensing potentiometer 194 will then permit the solenoid 41to be actuated upon the manual depression of the discharge switch 31 toopen the gate 19 of the hopper 14 at the will of the operator.

It will be apparent that tare weight compensation may be provide-d forthe embodiment of FIG. 4 by the use of means such as the clutch drivenpotentiometer illustrated in FIG. 3 (not shown) should it be so desiredto incorporate this feature.

The term switch means has been used throughout the specification andclaims herein and has been featured more specifically as a conventionalstepping switch. The term, however, is to be considered in its broadsense to incorporate other forms of sequentially operated switchingdevices and remain within the scope of the present invention.

It will be apparent that in each of the embodiments hereinabovedescribed, that circuit relationships have been set up for merely twodifferent materials A and B for purposes of simplicity of descriptionand illustration. However, it will be apparent to those skilled in theart that additional circuits respectively relating to additionalmaterials may be added as desired without departing from the scope ofthe present invention. It will also be apparent that in each of theembodiments of the present invention, either or both of the respectivepreset potentiometers may be motivated to any desired amount, and mayconclude a zero amount of the respective material, it so desired,without afiiecting any relationship of the other preset potentiometer orpotentiometers.

We claim:

1. An automatic control for delivery of materials from a plurality ofbulk sources to a common receiving means, comprising an integratingelectrical circuit arranged, for connection with a source of electricalenergy, and including comparative circuit portions, condition responsivemeans associated with said circuit portions and arranged to respond toan unbalanced circuit condition existing therebetween; one of siadcircuit portions being a material receiving responsive portion includingmeans for altering said portion in proportion to the accumulated amountof material delivered to said receiving means, and another of saidcomparative circuit portions being a preset portion including adjustablemeans for cumulatively altering that portion responsive to apreselective delivery of respective materials from said bulk sources;sequentially operated movable switch means arranged to be selectivelymoved to one of several switch contact positions responsive to anunbalanced circuit condition existing between said comparative circuitportions as reflected in said condition responsive means; electricallyoperated delivery control means for each of said bulk material sourcesand arranged to be selectively operated for delivery of the respectivematerial to said receiving means on motivation of said movable switchmeans to a respectively associated switch position, whereby the saidcomparative circuit portions will automatically integrate theaccumulated responsive condition to said condition response means formovement of said switch to its next succeeding switch contact positionsfor actuation of the respective delivery control means associated withthe remaining bulk sources, a presettable zero sensing potentiometercircuit, and means to connect said zero sensing potentiometer circuit ina comparative circuit relation to the circuit portion being the materialreceiving responsive portion and arranged to provide an unbalancedsignal to said amplifier upon removal of said materials from said commonreceiving means for purposes of resetting the cyclic operation of saidswitch means.

2. The automatic control of claim 1 having said presettable zero sensingpotentiometer circuit selectively connected in circuit by saidselectively movable switch means and thereafter holding the selectivelymovable switch means effectively inoperable prior to discharge of saidmaterials from said common receiving means, and means to release thematerial from said common receiving means and thereby reset said switchmeans for another delivery of. material.

3. An automatic control for delivery of materials from a plurality ofbulk sources to a common receiving means, comprising an integratingelectrical circuit arranged for connection with a source of electricalenergy, and including an electrical bridge having four arm portions ofwhich two arm portions each have a fixed resistance, a referencepotentiometer circuit portion comprising a third arm portion of saidbridge and having a movable contact arranged to be motivated directlyresponsive to the accumulated amount of material delivered to saidreceiving means, the fourth arm portion of said bridge comprising acomparative circuit portion including a plurality of manuallypresettable potentiometers respectively associated with each of saidmaterial bulk sources and each being arranged for establishing apredetermined balancing voltage division responsive to predetermineddelivery of a respective material; a signal amplifier arranged toprovide an amplified output circuit responsive to an unbalanced signalvoltage condition between the said comparative third and fourth armportions of said bridge; selectively movable switch means arranged to beselectively motivated to one of several switch contact posi tionsresponsive to an amplified output signal from said amplifier upon theoccurrence of a balanced circuit condition existing between saidcomparative arm portions; and electrically operated delivery controlmeans for each of said bulk material sources and arranged to beselectively operated for delivery of the respective material to saidcommon receiving means upon motivation of said movable switch means to arespectively associated switch position, whereby the said presetpotentiometer arm portions of the bridge and reference arm portion willautomatically integrate the accumulated input voltage signal to saidamplifier for movement of said switch to its next succeeding switchcontact positions for actuation of the respective delivery control meansassociated with the remaining bulk sources.

4. In an automatic control for delivery of materials from a plurality ofbulk sources to a common receiving means, a bridge circuit connectableto a power source and having a preset arm and a delivery responsive arm,said delivery responsive arm including a potentiometer having a movablecontact means coupled to the receiving means and positioned inaccordance with the material received therein, said preset arm includinga plurality of series connectable preset potentiometers having separablymovable contact means for positioning in accordance with the separatequantity of material to be delivered from the bulk sources, said presetarm further including a discharge sensing potentiometer having a movablecontact means, and a stepping switch having a first switch bank tosequentially operably connect the series connectable presetpotentiometer in the bridge circuit and thereafter the discharge sensingpotentiometer and having a second switch bank operated concurrently withsaid first switch bank to sequentially insert the several potentiometersin said series of preset potentiometers, and means operated by theoutput of the bridge circuit to control delivery of material from thebulk sources in accordance with the output of the bridge circuit and toactuate said stepping switch to automatically deliver material from saidbulk sources in accordance with the separate settings of said presetpotentiometers and to reset the stepping switch in response to dischargeof material from the common receiving means.

5. The construction of claim 4 wherein said last named r i 15 meansincludes a third switch bank of said stepping switch operatedconcurrently with the other switch banks, said third switch bank beingconnected to sequentially disenable all delivery from the bulk sources,separately enable delivery from the bulk sources, and finally enabledischarge from the common receiving means, and electro-responsive meansconnected to the output of said bridge circuit to sequentially actuatethe stepping switch.

References Cited in the'file of this patent UNITED STATES PATENTS2,046,693 McCrery July 7, 1936 16 Carliss Feb. 29, Lindars Aug. 6,Hollenbach Apr. 8, Hags Jan. 27, Kolisch Feb. 10, Bell Dec. 22, ThorssonMay 31, Burdick Oct. 17, Williams May 22,

4. IN AN AUTOMATIC CONTROL FOR DELIVERY OF MATERIALS FROM A PLURALITY OFBULK SOURCES TO A COMMON RECEIVING MEANS, A BRIDGE CIRCUIT CONNECTABLETO A POWER SOURCE AND HAVING A PRESET ARM AND A DELIVERY RESPONSIVE ARM,SAID DELIVERY RESPONSIVE ARM INCLUDING A POTENTIOMETER HAVING A MOVABLECONTACT MEANS COUPLED TO THE RECEIVING MEANS AND POSITIONED INACCORDANCE WITH THE MATERIAL RECEIVED THEREIN, SAID PRESET ARM INCLUDINGA PLURALITY OF SERIES CONNECTABLE PRESET POTENTIOMETERS HAVING SEPARABLYMOVABLE CONTACT MEANS FOR POSITIONING IN ACCORDANCE WITH THE SEPARATEQUANTITY OF MATERIAL TO BE DELIVERED FROM THE BULK SOURCES, SAID PRESETARM FURTHER INCLUDING A DISCHARGE SENSING POTENTIOMETER HAVING A MOVABLECONTACT MEANS, AND A STEPPING SWITCH HAVING A FIRST SWITCH BANK TOSEQUENTIALLY OPERABLY CONNECT THE SERIES CONNECTABLE PRESETPOTENTIOMETER IN THE BRIDGE CIRCUIT AND THEREAFTER THE DISCHARGE SENSINGPOTENTIOMETER AND HAVING A SECOND SWITCH BANK OPERATED CONCURRENTLY WITHSAID FIRST SWITCH BANK TO SEQUENTIALLY INSERT THE SEVERAL POTENTIOMETERSIN SAID SERIES OF PRESET POTENTIOMETERS, AND MEANS OPERATED BY THEOUTPUT OF THE BRIDGE CIRCUIT TO CONTROL DELIVERY OF MATERIAL FROM THEBULK SOURCES IN ACCORDANCE WITH THE OUTPUT OF THE BRIDGE CIRCUIT AND TOACTUATE SAID STEPPING SWITCH TO AUTOMATICALLY DELIVER MATERIAL FROM SAIDBULK SOURCES IN ACCORDANCE WITH THE SEPARATE SETTINGS OF SAID PRESETPOTENTIOMETERS AND TO RESET THE STEPPING SWITCH IN RESPONSE TO DISCHARGEOF MATERIAL FROM THE COMMON RECEIVING MEANS.